Related

Join the DigitalOcean Community Community

Join 1M+ other developers and:

  • Get help and share knowledge in Q&A
  • Subscribe to topics of interest
  • Get courses & tools that help you grow as a developer or small business owner
 Join Now
Connect to DB installed into dedicated VPS (private networking) Question Question
Is both HTTP and HTTPS versions should be verified in Webmaster Tools? Question Question

Question

How do I configure my firewall to allow SSH traffic for new the Remote Console / Recovery Console?

Posted August 27, 2021 168 views
CentOSSecurityFirewallDigitalOcean Droplets

I installed the new droplet-agent on my CentOS 7 droplet, but attempts to connect using the Droplet Console timed out.

I reasoned it was my firewall (iptables) setup. When I disabled iptables, the Console connected, using IP address 198.211.111.194. ARIN shows that CIDR 198.211.96.0/19 belongs to Digital Ocean, so that makes sense.

How do I configure iptables to safely allow only legitimate SSH traffic for the Droplet Console?

Thanks in advance for your help!

Add a comment
aknash
By:
aknash

Related

Join the DigitalOcean Community Community

Join 1M+ other developers and:

  • Get help and share knowledge in Q&A
  • Subscribe to topics of interest
  • Get courses & tools that help you grow as a developer or small business owner
 Join Now
Connect to DB installed into dedicated VPS (private networking) Question Question
Is both HTTP and HTTPS versions should be verified in Webmaster Tools? Question Question

These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.

×
Submit an Answer
1 answer
KFSys August 30, 2021

Hi @aknash,

Well, I’ll recommend allowing only IP addresses that are needed and only on PORTS that are meant to be used by such IPs.

To allow incoming SSH connections from a specific IP address or subnet, specify the source. For example, if you want to allow the entire 198.211.96.0/19 subnet, run these commands:

sudo iptables -A INPUT -p tcp -s 198.211.96.0/19 --dport 22 -m conntrack --ctstate NEW,ESTABLISHED -j ACCEPT
sudo iptables -A OUTPUT -p tcp --sport 22 -m conntrack --ctstate ESTABLISHED -j ACCEPT

The second command, which allows the outgoing traffic of established SSH connections, is only necessary if the OUTPUT policy is not set to ACCEPT.

Reply Report
  • aknash August 30, 2021

    Thanks!

    Yes, that’s my conclusion also: the console traffic is blocked because I have really tight firewall settings for SSH traffic. The DO subnet (198.211.96.0/19) involved is very large, and I’m leery of opening up the system to it. Wouldn’t some of those IPs be assigned to other DO droplets? I don’t know… but if so, that presents a huge security risk.

    Opened a support ticket but haven’t yet rec’d a definitive answer.

    Reply Report
    • KFSys September 2, 2021

      Hi @aknash,

      Yes, you are correct in your assumptions. BEtter to not allow the whole range of IP Addresses just because of the reasons you mentioned.

      As soon as you receive an answer, can you post it here, I’m eager to see what will happen out of this case?

      Reply Report

Related

Looking for something else?

Ask a new question Search for more help